Backstage stories I've heard is the legitimate bad ass in the back has always been the Undertaker. I've heard stories about him whooping up on wrestlers who disrespect him in the back and that includes Lesnar. But I've also heard a close second or just as bad isn't in the WWE anymore. And that would be your Olympic gold medalist Kurt Angle, oh it's true, it's damn true. I've heard he as also whooped up on Lesnar and pretty much had wrestlers afraid to wrestle him and mess up, because he would hurt you during or afterwards. I heard many wrestlers refer to Angle outside the ring as an absolute animal.